As Diana, the film about the final years of the late Princess of Wales,
premieres tonight, Alice Vincent finds out what to expect.

The film is an adaptation of Diana: Her Last Love, Kate Snell’s account of the two years between the late Princess of Wales’ divorce from Prince Charles and her death in 1997. It focuses on the relationship between Diana and heart surgeon Hasnat Khan, and suggests that Diana and Mr Khan were involved romantically for two years, and she nicknamed him “Mr Wonderful”.

Of the relationship itself, Mr Khan said that it broke down weeks before her death in 1997 because “after two years [it] wasn’t leading to a meaningful progression or conclusion.”

What have the Royal Family said?

So far, nothing. However, Buckingham Palace experts aren’t looking forward to the film. Ingrid Seward, editor of Majesty Magazine, told Sky News she thought the film would be “incredibly hurtful” for Princes Harry and William and that “once again their mother’s memory has been hijacked.”

Who is playing Diana?

Naomi Watts, who is 44 and was born in Britain but grew up and began her career in Australia. She was Oscar-nominated for Best Actress for her part in 21 Grams, and more award nominations followed for her performance in 2013 disaster movie The Impossible, about the 2004 Indian Ocean tsunami.

Will she be any good?

Until the reviews are in, the jury’s out. But Watts has discussed the film extensively. She turned down the role twice, finally agreeing when she realised it would be made with or without her and she “didn’t like the idea of anybody else playing the role”. Since then, Watts has admitted to The Sunday Times that she is anxious about the impact on the Royal Family, saying, “the biggest reason that made me pause was how the princes were going to feel about this.” One particularly awkward moment arrived when she saw Prince William in a restaurant and “got very nervous [and] made sure not to look” at him.

As for her preparations, Watts told The Telegraph that she had watched Diana’s famous interview with Martin Bashir “thousands with volume, without volume; and I listened to it over and over again until I knew every word of it” and studied the Princess of Wales’ voice, which she defined as “quite posh, but there was a warmth there, too. Her accent wasn't too fruity.”

Watts is also aware of her and Diana’s aesthetic differences, which the actresses’s critics have highlighted, saying: “Everyone was doubting, ‘Oh, she’s not the right height, she doesn’t have the right nose, she’s not properly British’ – all of those things I just had to let go of and commit to the role.”

Who is the director?

Oliver Hirschbiegel, a German director, who is best known for his film about Adolf Hitler’s last days, Downfall. He defended Diana, the film, to Sky News by saying it is based on the accounts of “several people” and asserting that it is “not a documentary but a dramatic interpretation. In a love story you have to create four or five dramatic scenes to make it work.”

When is it out?

The UK premiere is tonight, but you’ll have to wait until September 20 to see it in cinemas.